2009-2011: Juniors Giron won the boys' singles in the
Ojai Tennis Tournament in 2009 and the men’s invitational in 2011.
2020: First Major wins & top 100 Giron reached the second round of a major for the first time at the
US Open where he defeated
Marc Polmans in five sets. A month later, he reached the second round of the
French Open, defeating
Quentin Halys in five sets. In both victories, he came back from a two-sets-to-one deficit. In November, Giron recorded his first top-ten win against seventh seed
Matteo Berrettini at the
Paris Masters.
2021: Major third round, Olympics debut Giron started his 2021 season at the
Murray River Open, an event that was organized as a lead-up tournament to the Australian Open due to other tournaments in Australia being cancelled as a result from the
COVID-19 pandemic. He beat 10th seed,
Adrian Mannarino, in the second round. He lost in the third round to eighth seed and eventual champion,
Dan Evans. He participated in the main draw as a direct entry at the
Australian Open for a second consecutive year. He lost in the first round to sixth seed and world No. 7,
Alexander Zverev, in four sets. At the
Open Sud de France, Giron was defeated in the first round by qualifier
Tallon Griekspoor. Getting past qualifying at the
Rotterdam Open, he was eliminated in the first round by fourth seed, world No. 8, and eventual champion,
Andrey Rublev. In June, Giron reached the third round of a major at the
French Open for the first time in his career. At
Halle, Giron reached his first quarterfinal at an
ATP 500 level tournament as a qualifier where he was defeated by
Félix Auger-Aliassime. As a result of this good run, he reached a then career-high of No. 65 on 21 June 2021. Giron made the second round at the
Olympics, beating
Norbert Gombos before losing to
Kei Nishikori in three sets. In September at the
Sofia Open, Giron reached his fourth quarterfinal of the season (with quarterfinal appearances in Halle, Metz and Winston-Salem) after defeating third seed
Alex de Minaur in the second round. He later beat 8th seed
John Millman in 70 minutes to move into his first career ATP tour-level semifinal, where he lost to second seed
Gaël Monfils. As a result, he reached a new career-high ranking in the top 60, at world No. 59 on 4 October 2021.
2022: Top 50 & first ATP Tour final Giron started his 2022 season at the first edition of the
Melbourne Summer Set 1. He lost in the first round to qualifier
Ričardas Berankis. At the
Sydney Classic, he was defeated in the first round by Australian wildcard
Jordan Thompson. At the
Australian Open, he was beaten in the first round by sixth seed, world No. 5, and eventual champion
Rafael Nadal. Seeded seventh at the first edition of the
Dallas Open, Giron upset world No. 19
Taylor Fritz in the quarterfinals to reach his second ATP tour semifinal. He lost in his semifinal match to fourth seed
Jenson Brooksby in three sets despite holding four match points. In
Delray Beach, he was defeated in the second round by
John Millman. At the
Mexican Open in Acapulco, he upset eighth seed and world No. 17
Pablo Carreño Busta in the second round. He lost in the quarterfinals to third seed and world No. 4
Stefanos Tsitsipas. At the
Indian Wells Masters, he was eliminated in the first round by
Lorenzo Musetti. In
Miami, he lost in the first round to
Márton Fucsovics. Giron started his clay court season at the
U.S. Men's Clay Court Championships. He lost in the first round to world No. 30
Frances Tiafoe. At the
Monte-Carlo Masters, he was defeated in the first round by eventual finalist
Alejandro Davidovich Fokina. In
Barcelona, he lost in the first round to
Federico Coria. At the
BMW Open in
Munich, he fell in the first round to
Hugo Gaston. At the
Madrid Open, he lost in the first round of qualifying to
Alejandro Tabilo. On his debut at the
Italian Open as a lucky loser, he upset 12th seed
Diego Schwartzman in the second round. He lost in the third round to
Félix Auger-Aliassime. In
Geneva, he lost in the first round to
Ilya Ivashka. He made his top 50 debut on 16 May 2022. At the
French Open, he was defeated in the first round by
Grigor Dimitrov. Giron started his grass court season at the
BOSS Open in
Stuttgart. He lost in the first round to German wildcard
Jan-Lennard Struff, despite having two match points in the third set
tiebreak. At the
Halle Open, he was defeated in the first round by Félix Auger-Aliassime. In
Mallorca, he reached the quarterfinals where he lost to second seed Stefanos Tsitsipas. At
Wimbledon, he upset 24th seed
Holger Rune in the first round. He lost in the second round to
Alex Molčan. Giron started his US Open series at the
Atlanta Open. He lost in the first round to
Kwon Soon-woo despite leading by a break in the third set. At the
Citi Open in
Washington, D.C., he was defeated in the first round by eventual champion
Nick Kyrgios. Getting past qualifying at the
National Bank Open in Montreal, he lost in the first round to
Roberto Bautista Agut. Making it past qualifying at the
Western & Southern Open, he beat
David Goffin in the first round. He was defeated in the second round by
Bautista Agut. At the
US Open, he lost in the first round to Frances Tiafoe. Seeded third at the
San Diego Open, Giron reached his maiden ATP tour final after defeating
Dan Evans in his semifinal match. He lost in the final to
Brandon Nakashima. Competing at the first edition of the
Gijón Open, he was defeated in the second round by
Dominic Thiem in three sets. In
Antwerp, he lost in the first round to
Sebastian Korda. At the
Erste Bank Open in
Vienna, he upset
Cameron Norrie in the second round. He lost in his quarterfinal match to
Grigor Dimitrov.
2023: French third round, two top 10 wins Giron started his 2023 season at the
Adelaide International 1. He lost in the second round to Australian qualifier
Alexei Popyrin. In
Auckland, he reached the quarterfinals where he was defeated by second seed
Cameron Norrie. At the
Australian Open, he lost in the first round to
Daniil Medvedev. Seeded seventh at the
Dallas Open, Giron made it to the quarterfinals where he was beaten by top seed
Taylor Fritz in a rematch from last year. At the
Delray Beach Open, he upset eighth seed
Ben Shelton in the first round. In the second round, he ended the dream ATP Tour debut of 33-year-old qualifier
Matija Pecotić. He lost in his quarterfinal match to
Miomir Kecmanović. In
Acapulco, he was defeated in the first round by compatriot
Michael Mmoh. At the
BNP Paribas Open, he was eliminated from the tournament in the second round by
Frances Tiafoe. At the
Miami Open, he fell in the first round to qualifier
Cristian Garín. Giron started his clay-court season at the
U.S. Men's Clay Court Championships. Seeded seventh, he lost in the second round to qualifier
Tomáš Macháč. At the
BMW Open, he upset seventh seed
Roberto Carballés Baena in the first round. He ended up reaching the quarterfinals where he was defeated by
Botic van de Zandschulp. Playing at the
Madrid Open, he lost in the second round to 25th seed
Sebastián Báez. He reached the third round at the
2023 French Open for a second time in his career and overall at a Major level defeating qualifier
Hamad Međedović and
Jiří Lehečka. Giron qualified for the
Canadian Open, with wins over
Nick Chappell and
Radu Albot. After defeating
Emil Ruusuvuori in the first round, he upset world No. 6
Holger Rune in three sets, the biggest win of his career and second top-10 win. He then lost to compatriot
Tommy Paul in the third round. At the ATP 500
2023 Japan Open Tennis Championships he reached the semifinals as a qualifier after defeating home favorite
Yoshihito Nishioka, second seed
Casper Ruud, his third top-10 win, and eight seed
Félix Auger-Aliassime, last two matches in straight sets. Giron was coached by former
UCLA teammate
Karue Sell during the
2023 season.
2024: First ATP title, top 40 Giron reached his second ATP final at the
2024 Dallas Open defeating top seed
Frances Tiafoe and fourth seed
Adrian Mannarino in straight sets before losing to
Tommy Paul. The following week at the
2024 Delray Beach Open, he reached for the first time a consecutive ATP semifinal (his sixth in his career), defeating
Emilio Nava, again fourth seed Adrian Mannarino this time in three sets, and wildcard
Patrick Kypson. He lost to defending champion and top seed
Taylor Fritz in straight sets. As a result he reached a new career-high ranking in the top 45 on 19 February 2024. At the beginning of the grass season, at the
2024 BOSS Open in Stuttgart, Giron defeated
Andy Murray. In
Halle, he upset fourth seed
Andrey Rublev, his first top 10 win on this surface, to reach the round of 16. Next he defeated
Matteo Berrettini in three sets to reach the quarterfinals. His good form continued at the next grass court tournament, the
2024 Eastbourne International where he defeated defending champion and fifth seed
Francisco Cerundolo in the first round. At the
2024 Wimbledon Championships, he also reached the second round with a win over wildcard
Henry Searle. Giron won his first ATP title at the
2024 Hall of Fame Open, defeating
Alex Michelsen in the final making him the
tenth first-time ATP Tour champion for 2024. En route to the title, he registered wins over
Alex Bolt in the quarterfinals and
Christopher Eubanks in the last four. As a result he reached a new career-high ranking of No. 38 on 22 July 2024.
2025: Masters fourth round, top 5 wins Giron reached the third round of the
2025 Australian Open for the first time defeating
Tomas Martin Etcheverry in five sets. At the
2025 BNP Paribas Open Giron took out the world No. 5 and fourth seed
Casper Ruud to reach the third round at the tournament for the second time. It was his first top 5 win in his career. He followed that with toppling down another seeded player, 26th seed
Alexei Popyrin to reach a Masters fourth round for the first time in his career.
2026: Consecutive ATP semifinals, ATP 175 final After reaching consecutive ATP semifinals in
Hong Kong and at the
2026 ASB Classic in Auckland, Giron reached another semifinal at the
2026 Arizona Classic in Phoenix, with wins over
Jay Friend and defending champion
Nuno Borges. He went one step further and reached the final defeating top seed
Corentin Moutet in the semifinal. ==Singles performance timeline==